Timer.



F. C HERSEE & L. W. LOMBARD.

TIMER.

APPLICATION FILED- MAY 28. I914.

Patented Apr. 27, 1915.

THE NORRIS PETERS (20., PHOTD-LITHOV. WASHINGTON. L). C.

UNITED STATES PATENT oEEioE.

FREDERICK C. HERSEE, OF ROSLINDALE, AND LEVI W. LOMBARD, OF WALTHAM, MASSACHUSETTS, ASSIGNORS TO MOTOR SPECIALTIES COMPANY, OF WALTHAM, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

TIMER.

Specification of Letters Patent.

Application filed May 28, 1914. Serial No. 841,643.

To all whom it may concern Be it known that we, FREDERICK C. HER- sEE and LEVI 1V. LOMBARD, citizens of the United States, and residents, respectively, of Roslindale, county of Suffolk, Commonwealth of Massachusetts, and \Valtham, county of Middlesex, Commonwealth of Massachusetts, have invented an Improvement in Timers, of which the following description, in connection with the accompanying drawings, is a specification, l ke characters on the drawings representing like parts in each of the several views.

This invention relates to timers for the ignition of internal combustion engines, of the type wherein an electric contact is eccentrically carried by a rotating eng ne driven shaft for periodic engagement with cooperative fixed contacts for complet ng the circuit and properly timing the igniting spark.

A prime object of the invention is to provide such a timer with means whereby at a predetermined speed of the engine the spark will be discontinued so long as such excessive speed is maintained, and again pro duced as soon as the speed is reduced below such limit. To this end we preferably provide a centrifugally operating circuit breaker specially arranged in connection with the timer and having provision for convenient adjustment so that the speed at which the spark will be discontinued can be varied as required.

A further object of the invention is to provide improved means for insuring effective action of the cooperating contacts at all times, by constantly shifting the contacting areas at each cont-act.

The above and other objects and features of the invention will be better understood from the following detailed description taken in connection with the accompanying drawings.

Referring to the drawings: Figure 1 s a central lengthwise vertical section showing a preferred embodiment of our improved timer; Fig. 2 is a transverse vertical section thereof on line 22 of Fig. 1; Fig. 3 is a detail transverse section taken at the end of the timer shaft; and Fig. 4 is a fragmentary detail showing particularly the centrifugal circuit breaking means.

A fragmentary portion of the engine casing is indicated at 1 having an engine driven shaft 2 extending and fitted thereinto. The shaft 2 has its end formed with an enlarged head 3 which turns in a recess or bore 1 of the casing. The shaft head 3 is formed with a peripheral annular groove or recess 5 affording clearance for a series of spring pressed contacts 6 which thus extend within the circumference of the head 3. These contacts are spaced around the casing extension 1 in a number determined by the number of engine cylinders to be controlled. The con tacts 6 which are shown as balls are mounted to turn in sockets in the inner ends of posts 7 slidably fitted in insulating bushings 8 of fiber or the like, set in radial passages of the casing with interposed springs 9 to press them inward as far as permitted by the stop nuts 10 threaded on the outer ends of said posts. The shaft head 3 is formed at one side with a deep pocket 11 intersecting the annular groove 5 and in this pocket is fitted a spool 12 carried on a bearing pin 13 set into a socket of the shaft incased in fiber or other suitable insulation as seen at- 11. The spool 12 does not touch the walls of the pocket in which it is contained and its inner end is separated from the adjacent wall of the shaft by an insulating layer 15 so that said spool is insulated from the shaft. The periphery of the spool 12 is shown as of a shallow V-shape in cross section as seen at 16 affording a sloping surface for engagement by the spring pressed contacts 6, and these contacts being formed as balls socketed to turn freely, it follows that each time a contact is made, a contacting ball 6 and the spool 12 will each be turned some little so that the contacting surfaces are constantly being changed and renewed.

At the end of the shaft head 3 is fixed as by screws 17 a metallic disk 18 serving as a carrier and mounting for a centrifugal cir cuit breaking device which is shown as consisting in two oppositely arranged blocks 19 of lobe form pivoted at 20 on opposite sides of said disk. To make the mounting of these lobes more secure we preferably form the pivots 20 as stout posts set into the disk 18 and fit another disk 21 at their outer ends which interbraces them and makes them more rigid. The centrifugal blocks 19 are Patented Apr. 27, 1915.

normally drawn toward each other so that their inner sides press against and make contact with a transverse pin 22, by a spring 23 reacting between said blocks being fixedly secured to one of them at 2-1 and having its other end adjustably secured in the other block by a screw 25 threaded in said block. The outer end of this screw is formed for engagement with an operating tool and we provide a radial passage 26 in the casing in position to register and aline with this screw in one position of the shaft so that it can be conveniently adjusted. The transverse pin 22 is carried by a post 27 set in an insulating bushing 28 fixed in the disk 18 and the inner end of this post is in electrical connection with the pivot post 13 of roller 12 through a spring presser plate 29 carried by said post and pressing against the end of the pivot post 13. The end of the casing bore which contains the operating parts just described may be closed by a screw cap 30 which may be equipped with an anti-friction thrust ball bearing 31 adapted to engage the end disk 21 centrally thereof.

It may now be understood that with one terminal of the magneto circuit grounded on the casing 1, as is usual, and the other terminal connected with the respective posts 7 the circuit will be completed at the proper intervals to produce sparks for ignition by the contacts of the roller 12 with the successive balls 6. It will further be understood that in our improved construction, since the circuit does not pass directly from the roller 12 to the casing, but instead said roller is only connected electrically with the casing through the contact 29, post 27 and pin 22, to the centrifugal blocks 19, which are electrically connected with the casing by their metallic pivots, it follows that the circuit is only complete for sparking action so long as the blocks 19 rest against the ends of the pin 22 as held by the spring 23. It may thus be seen that as soon as the engine is speeded up to a predetermined rate, the blocks 19 under the action of centrifugal force will swing outward and break the connection. The speed rate at which this will occur can be readily varied as required merely by inserting a screw driver through the radial passage 26 and adjusting the screw 25 in or out to the necessary extent. Thus a cut-out is provided adapted to act with absolute certainty for stopping the power of the engine when its rate of speed reaches a predetermined maximum, and since the centrifugal members 19 will again move in and contact with the pin 22 as soon as the rate of speed is reduced, it will be seen that the governor thus provided is adapted to act instantly and reliably to restore the power of the engine when the speed is reduced below a predetermined limit.

We are aware that the invention can be embodied in other specific forms varied as to details of construction and we therefore desire the present embodiment to be considered as illustrative and not restrictive and refer rather to the appended claims to indicate the scope of the invention.

'Having described our invention, what we claim as new and desire to secure by Letters Patent is:

1. A timer, comprising a relatively fixed contact, a relatively movable contact for cooperation therewith, a rotary shaft on which said movable contact is eccentrically mounted, said fixed contact being positioned outside the orbit of said movable contact, and means carried by said shaft and normally completing the circuit from said movable contact, for breaking the circuit when the rate of rotation of said shaft rises to a predetermined limit, said means being mounted on the end of said shaft and lying substantially within the radial limits of the orbit of said movable contact.

2. A timer, comprising a relatively fixed contact, a movable contact mounted for co operation therewith, a shaft on which said movable contact is eccentrically mounted, and a centrifugal circuit breaker interposed in the circuit from said movable contact adapted to break connection from said movable contact when the speed of shaft rotation rises to a predetermined limit, said circuit breaker being mounted on the end of said shaft and lying substantially within the radial limits of the orbit of said movable contact.

3. A timer, comprising cooperative relatively fixed and movable contacts, a shaft on which the movable contact is carried, and a centrifugal circuit breaker interposed in the connection from said movable contact consisting in a pair of oppositely disposed swingingly mounted blocks equipped with a spring for normally drawing them toward each other and a contact element interposed between said blocks and normally co-acting therewith to complete the circuit.

4. A timer, comprising a fixed casing having fitted therein an insulated contact, a shaft having a movable contact to cooperate therewith, and a centrifugal circuit breaker normally completing the circuit from said movable contact, having a spring normally holding the circuit closed, and means for adjusting the tension of said spring, there being a passage through the casing permitting access to said adjusting means, said circuit breaker being mounted on the end of said shaft and being of relatively small radial dimension.

5. A timer, comprising a casing having insulated contacts fitted therein, a shaft having a movable contact eccentrically mounted for cooperation with said casing contacts, said movable contact being insulated from said shaft, a centrifugal circuit breaker carried by said shaft having a centrifugally acting element in electrical connection with the shaft, and a conducting element in electrical connection with said movable contact and normally in position to be engaged by said centrifugally acting element.

6. A timer, comprising a casing having a relatively fixed contact fitted therein, a shaft bearing a movable contact for cooperation with said fixed contact, and a centrifugal circuit breaker mounted on the end of said shaft and normally completing the circuit from said movable contact, said circuit breaker having a pair of oppositely arranged swingingly mounted blocks with a transversely extending conductive element therebetween to be normally engaged thereby for completing the circuit, a spring having its ends engaged with said blocks for drawing them toward each other and against said conductive element, and a screw for adjusting the tension of said spring.

7. A timer, comprising a casing having a relatively fixed contact mounted therein consisting in a ball with a yielding socket mounting, a shaft having an enlarged head formed with a peripheral groove into which said ball extends, and a movable contact consisting in a roller eccentrically mounted in said shaft, and intersecting said peripheral groove, said roller having a V- shaped recess in its periphery, on one side of which said ball engages.

In testimony whereof, we have signed our names to this specification, in the presence of two subscribing witnesses.

FREDERICK C. HERSEE. LEVI W. LOMBARD. Witnesses:

M. R. HARRIS, C. F. VAUGHAN.

G'opies of this patent may be obtained for five cents each, by addressing the Commissioner of Patent;

Washington, D. 0." 

